1. Field of the Invention
The invention is directed to a device for the multi-axis adjustment of a plurality of elements relative to one another, wherein the elements are rotatable relative to one another via two or more bearings having differently oriented axes of rotation, and wherein each bearing has two parts that can be rotated relative to each other about their respective axes of rotation, particularly to a hub of a wind turbine having rotor blades that are mounted to the hub by means of blade bearings and can be adjusted about their respective longitudinal axes.
2. Description of the Prior Art
Modern large rolling bearings have diameters above the 2-meter range in many applications, and use cases involving diameters of 5 or even 8 meters are not uncommon nowadays. One example of such an application is modern wind turbines, whose wind wheels are constantly being built larger to increase performance. The larger the diameter of such a bearing, the more important its rigidity, since even slight deformation of the bearing rings will alter the pressure on the rolling elements, not only causing greater losses, but also reducing the achievable service life of the rings. On the other hand, increased rigidity means an increased thickness for the rings, and thus, of course, a larger mass, i.e., a greater weight. Since this is unacceptable in many applications, the mating structure itself is usually enlisted to increase rigidity; this does not substantially change much either, however, since the weight of the mating structure then increases as well, leading to the same disadvantages in most cases. This is especially true of wind turbines, where a number of large rolling bearings are installed, here as gondola or nacelle bearings, there as main or rotor bearings for the rotating wind wheel, and finally as blade bearings for adjusting the rotor blades as a function of wind speed.